Earth-boring tools are used to form boreholes (e.g., wellbores) in subterranean formations. Such earth-boring tools include, for example, drill bits, reamers, mills, etc. For example, roller cone bits (also termed “rock” bits) as well as fixed-cutter earth-boring rotary drill bits (often referred to as a “drag” bits) have relatively long service lives, with relatively infrequent failure. In particular, considerable sums are expended to design and manufacture roller cone rock bits and fixed-cutter bits in a manner that minimizes the opportunity for catastrophic drill bit failure during drilling operations. The loss of a roller cone or a polycrystalline diamond compact (PDC) from a fixed-cutter bit during drilling operations can impede the drilling operations and, at worst, necessitate rather expensive fishing operations to retrieve the lost component. If the fishing operations fail, sidetrack-drilling operations must be performed in order to drill around the portion of the wellbore that includes the lost roller cones or PDC cutters.
Typically, during drilling operations, bits are pulled and replaced with new bits even though significant service could be obtained from the replaced bit. These premature replacements of downhole drill bits are expensive, since each trip out of the well prolongs the overall drilling activity by wasting valuable rig time and consumes considerable manpower, but are nevertheless done in order to avoid the far more disruptive and expensive process of, at best, pulling the drill string and replacing the bit or fishing and sidetrack drilling operations necessary if one or more cones or compacts are lost due to bit failure.
In addition to drilling operations, the loss of components secured to tool bodies could also prove to be disruptive and expensive for a variety of downhole operations, including, for example, reaming, logging, testing, coring, and production. In particular, many components are secured to downhole tools by removable fasteners that may become loose (i.e., back off) due to vibration, which may give rise to tool failure during downhole operations.